Carrier route record
DLAUS→SEA
Delta Air Lines · Austin to Seattle
- Flights
- 935
- Period
- July 2025 to June 2026
- Share of route
- 45%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on AUS to SEA earns a B. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 935 flights, with a median arrival 10 minutes early.
Set against the rest of the country, Delta's AUS to SEA record is 7 points better than the US average of 77.6%. That gap is worth roughly 73 fewer late arrivals for every thousand flights.
Key figures
On time
84.9%
Arrivals under 15 minutes late, of 923 completed flights
Avg delay
94 min
Across delayed arrivals only, not all flights
Cancelled
1.07%
National rate is 1.81%
Whole route
82.8%
Every carrier on AUS to SEA, 2,058 flights
These figures cover 935 flights between July 2025 and June 2026. The median arrival is 10 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
Delta against every carrier on AUS to SEA
Delta flew 935 of the 2,058 flights on AUS to SEA, about 45% of it. Its 84.9% on time is 2 points better than the route as a whole, which runs 82.8%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Delta at 84.9% to Southwest at 42.3%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines (this page) | 935 | 84.9% | 94 min | 1.07% | B |
| Alaska Airlines | 1,096 | 82.0% | 55 min | 1.00% | B |
| Southwest Airlinesthin sample | 27 | 42.3% | 36 min | 3.70% | F− |
Flight by flight
Delta flight numbers on AUS to SEA
Departure window
When Delta runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 16 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am325 flights91.9%
- 8am–11am—
- 11am–2pm278 flights87.6%
- 2pm–5pm21 flights—
- 5pm–8pm311 flights75.5%
- 8pm–5am—
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 91.9% of the time, against 75.5% for the evening window. That is 16 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 325 flights scheduled in it.
Across the year
Delta on AUS to SEA through the year
December is the weak month at 70.7% on time, against 91.9% in April. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. May was the busiest month here, with 92 flights.
Across the week, Saturday is the strongest day at 89.4% on time and Thursday the weakest at 78.5%. 11 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Delta runs late on this route
One category carries most of the weight here. Carrier accounts for 54% of the 13,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 54%Carrier
- 34%Late-arriving aircraft
- 8%National Airspace System
- 5%Extreme weather
The largest share of delay minutes, 54%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 6,969 of the 13,000 delay minutes reported here. The split is drawn from 13,019 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 91.9% on time here.
Cancellations sit at 1.07% against a national 1.81%, which is ordinary. Diversions add another 0.21%.
Connections and stage length
What a delay here costs
6.0% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last an hour and a half, which a normal layover absorbs.
At 1,770 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 81.0% on time across 936 flights, 4 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 4 points of difference.
One caution: this is a thin sample. 935 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Delta on AUS to SEA
Put together: treat all of this as provisional. 935 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 84.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 923 completed flights over 12 months sit behind that.
Related
Where to go next
- AUS to SEA, every carrier
- Delta on SEA to AUS, the return leg
- Alaska Airlines on AUS to SEA82.0%
- Delta Air Lines network-wide record
- Austin-Bergstrom International (AUS) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.